Is black oil a bad thing?

[Mystic]

Think about it a little bit. My Dad worked for a used car dealer (as a mechanic) after he retired from the construction company he worked for.

Especially if you are looking at used cars and trucks at a new car dealership or at a delaership that has some kind of a guarantee about the quality of their used cars. You check the dipstick on a used car or a used truck and the oil is black. Bingo! They do not even change the oil at that new car dealership or used car dealership. How can they have a guarantee about a vehicle when they don't even bother to change the oil? If they can't trouble themselves to even change the oil have they really gone over that car or truck very much? It is a sure giveaway. Changing the oil helps make a good first impression with a customer who is wise enough to take a look at the engine. There are other things to look for, like black smoke from the tailpipe and other stuff of course. Somebody who really knows their stuff can check out a car or truck somewhat even without tools. You can, if you look carefully enough, spot body damage, water damage, and other stuff. Better take a good look-lots of cars and trucks that were trashed in New Orleans were shipped to other parts of the country. Better take a good look. Always take a good look. Remember, if the car or truck was so great why did the last owner get rid of it? And there are good used car dealers but a lot of used car dealers fit the old image of the dishonest salesman. For that matter I could name a few new car dealers that fit the image.

 

[SteveD2]

I have seen some scary used cars.

 

[SteveD2]

Mystic,
When I am looking at a used car. I look and see if the tail pipe is black if so...I put my fingers in the tail pipe (to feel the soot, and look for oil). An oily tail pipe is bad. If there's lots of soot, its running rich or somebody drove the ________ out of it (I don't look at this as a bad thing just Observation). Next, I get someone to start the car, while I am watching the tail pipe, then I ask him to floor it

, while my eyes are on the tailpipe. There better not be any smoke.

 

[OriginHacker21]

I've run oil in my 2.2L ecotec for 7500 and it was still a golden brown color (dark brown). Never had oil turn black in this car - but I'm a pretty easy driver. I have noticed recently that as I drive harder and do more city driving (stop and go) - the oil darkens a lot quicker than if I drive my work route (220 miles/day - 110 miles one way).

 

[SteveD2]

OriginHacker21,
Its sounds like your engine will last many trouble free miles.

 

[tsmay51]

I have a 2003 dodge cummins diesel. Diesel motors are typically known to turn the oil black very quickly. For some odd reason mine stays very clean for a diesel. I have been doing 5k oci and it is still transparent and a tad darker. That's running rotella 15w40 and mobil 1 filters. I think I am gonna take this oci out to 6k though and see what it looks like.

 

[sootyoil]

Quote:

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I just bought a new leftover 06 Yukon demo with 3300 miles..the oil was black...changed it to castrol gtx and ran that a week......drained it tonight...almost black...just filled with mobil1...I know it will be black in 1000 miles. All my cars & boats turn the oil black with the exception of the wifes Lexus Rx330 which takes 5000 miles to turn it black and thats the oci. ALl of my GM engines have turned the oil black in 1000-1500 miles. But I always change at 2500-3000 miles.

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the oil in my Ford Taurus stays clean for 8/10 thousand miles, then for the next 10 thousand miles it turns golden brown and drains out dark brown at 20/25 thousand miles.
not bad for 1 year 6 month service with only a gallon of make up oil

my old truck F-250 diesel IDI has 40 thousand on the oil now, that has been in there since 2003 and pulling over 22+ mpg currently but that oil is black

 

[SteveD2]

Quote:

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I have a 2003 dodge cummins diesel. Diesel motors are typically known to turn the oil black very quickly. For some odd reason mine stays very clean for a diesel. I have been doing 5k oci and it is still transparent and a tad darker. That's running rotella 15w40 and mobil 1 filters. I think I am gonna take this oci out to 6k though and see what it looks like.

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My old man owns a 2001 Dodge Diesel. He also uses Rotella 15w40. But he changes it every 6000 Miles. It has over 160,000miles on the clock. The oil is never black, but very dark before the oil change.

 

[SteveD2]

Quote:

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the oil in my Ford Taurus stays clean for 8/10 thousand miles, then for the next 10 thousand miles it turns golden brown and drains out dark brown at 20/25 thousand miles.

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Are you running a bypass filter?

 

[SWS]

Rather than make simple blanket statements about oil color, I offer that for gasoline engines oil color is significant on a case-by-case basis, especially SUDDEN CHANGES in oil color. For example, on my 4 cars the oil stays honey colored for at least 6 months (using M1 EP), so that is the characteristic I look for. So if I observe the oil suddenly turn dark within that 6 month period, then I would look for a problem, such as a leak past the air filter, etc.

I don't know about diesel engines, but with the rather tight, fuel-injected gasoline engines that are built today -and- the better motor oils now offered, I think that the overall trend should be that gasoline engine oils would stay clearer for a longer time than in the past. However, I understand that some gasoline engines tend to turn oil dark very quickly, yet have no problems and enjoy long life. I would be interested to learn what causes this.